As the performance of an electronic device is enhanced there is also an increased requirement for heat dissipation as greater power is utilized. Typical of such an environment is high performance computers where capability is commonly measured in floating point operations per second (flops). Faster microprocessors usually require the use of larger amounts of power. Since it is desirable for performance and reliability to maintain the microprocessor's active metallurgy at a specified temperature, and since the power consumed by the microprocessor is dissipated as heat, advanced heat transfer structures and methods are needed. With the combined challenge of more numerous and powerful microprocessors in a given package, the limits of air cooling are easily exceeded. Traditional thermal interface materials are unable to provide necessary heat transfer required for effectively cooling the multi core modulus.
The structure and method of the present invention utilizes indium as a metallic thermal interface for enhanced heat transfer between a multi chip module, containing a plurality of high performance processor chips and a heat sink. Although indium is an effective thermal transfer material, it is susceptible to corrosion when it is in contact with silicon at 85 degrees C. and 85% relative humidity and also reacts with air to form an oxide with poor thermal conduction properties. Accordingly, to use indium as a thermal interface it is necessary to create a corrosion free environment. The present invention is directed to a cooling mechanism including an indium thermal interface material which is contained within a module-heat sink interface which is evacuated and sealed using a modified threaded heat sink. The interface with metallic indium forms a covalent bond with the heat sink surface.